Amblyopia (lazy eye) and strabismus (misaligned eyes) are medical eye conditions that combine as the leading causes of preventable vision loss in children. They are irreversible if not detected and corrected by the age of seven, however half of all cases are missed because the conditions do not always manifest themselves and pediatricians are unable to reliably detect the conditions. The current health care system badly needs an accurate and effective approach toward detecting amblyopia and strabismus in preschool children, and this application aims to show that REBIScan's Pediatric Vision Scanner is capable of detecting disease, including the most difficult for providers to diagnose, with a hig level of accuracy within a primary clinic with lay users as screeners. The study will be conducted in busy, ethnically and racially diverse primary care sites operated by the Kaiser Permanente system, with outcomes and efficiency of testing compared to the current standard of care. The research proposed in this SBIR application will complete the last significant milestones necessary for commercialization of the PVS. While the technology has been tested in enriched populations, there are no studies that test device performance when lay users perform testing in a busy pediatric setting, and usability has not been tested in the primary care setting. The Specific Aims will advance the health outcomes of children by using a scientifically rigorous approach to provide the efficiency and accuracy data that clinicians, investors, and payors require before the PVS can be adopted commercially. A two-phase study has been designed to compare the Pediatric Vision Scanner to the standard of care today. The first phase includes a sample population of older children in whom a limited Gold Standard Examination (visual acuity testing and non-cycloplegic autorefraction) is easily performed by a non-specialist in the primary care clinic. A linkage study will then be performed on a larger group of younger children who will receive the complete Gold Standard Examination. If the results of this study are similar to published studies performed with enriched populations, then the NIH will have funded a technology that has the potential to change the world and the way it detects amblyopia and strabismus.